Evaluate the following expression when $a = 3$ and $b = 8$. $3$ $a$ $ + 9$ $b$ $ - 3$
Explanation: Substitute $3$ for ${a}$ and $8$ for ${b}$ $ = 3{(3)} + 9{(8)} - 3 $ $ = 9 + 72 - 3 $ $ = 78$